Calculation of Power Transformer Short-current Force

This research studies the magnetic field and forces on the windings of transformer due to short-circuit. Three dimensional finite element computation of three-phase power transformer is carried out. The model developed have been applied to power transformer and the results are verified experimentally. To verify the computation results, they are compared with those obtained using ANSYS software simulation. In this paper a new optimal design of soccer robot control system which is based on mechanical analyses and calculations on the pressure and transmutation states of chip kick mechanics, this new control system with high precision for speed control and high dynamic quality. One of major reason for fault in power transformers is deterioration of winding and insulation of conductors due to the oscillations resulted from the electrodynamics forces. The over-current and rated current result in the above-mentioned forces. Therefore, the transformers coils must be protected mechanically and connected to each other by ribbon and wedges. The structural criterion for this support is generally those forces that are generated by the maximum possible current (1). A large transient current during a short-circuit apply abnormal electromechanical forces upon the windings of transformer that may damage the whole windings. Short-circuit forces and resultant stresses must be predicted in the design stage. These forces must be in the range that is specified by manufacturer. The accurate evaluation of the magnetic field and the resulting forces on power transformer windings under short-circuit is very important for the design of the device. It enables, in particular, to avoid mechanical damages and failures during short circuit tests and the power system faults. As the forces grow rapidly with the transformer rating their prediction is of crucial importance for the design of very large apparatus. In such cases short-circuit magnetic field and force tests under normal voltage are very laborious and expensive. The computation results are compared with those obtained by application of finite element method. Cause of Short-Circuit Magnetic Field and its Currents After a transformer is connected to current pass a transient mode and then reaches the steady-state mode . windings magnetic field of power transformer is a typical 3D nonlinear eddy current problem with a multiply connected region. In the region of windings, the field equations and boundary conditions is reflected the intensity of magnetic induction B.In the case of frequency,Ignore the impact of displacement current . Maxwell's equations as in